Beyond Birdseed

In Pennsylvania, it's not unusual to see bird feeders in local yards and gardens. Feeding birds is a popular activity in the United States and it's estimated that more than 50 million households participate. These backyard birdfeeders usually offer seeds, and occasionally suet, which provide nourishment for adult birds. But what about baby birds? 

Most baby birds are unable to feed on seeds. Like human infants, they need special food until they have grown and developed to the point where they are able to eat an adult diet. What can baby birds eat? Spiders and insects, especially caterpillars, and plenty of them.  They provide the proteins, fats, and other nutrients baby birds need to grow. Research has found that more than 5000 caterpillars are needed to raise a single nest of five baby Chickadees. Without insects, baby birds can literally starve to death.

Bird populations in North America have been declining for years. Results of a study (Rosenberg, et al.) released in 2019 showed a loss of 3 billion birds, or a 29% decline in the population of birds since 1970. While many factors contribute to declining bird populations, loss of habitat and pesticide use stand out among them. As wild areas are lost to development and agriculture, the trees, shrubs, and plants that birds and insects need for food and habitat disappear as well.  In addition, pesticides threaten both the plants and the insects that are so critical to the survival of birds. Yet birds play an important role in our very interconnected world.  They spread seeds, control insects, and help with pollination. Although we sometimes value them for their songs and their beauty, it's important to remember that they do their part in helping to maintain the balance of nature.

Looking at a residential neighborhood filled with green lawns, trees, shrubs, and flowers, it's easy to think that, at least here in our own backyards, birds and insects can find what they need. But that's not always the case. In fact, all too often, it's just the opposite.

Unfortunately, many backyards across the country are home to very few caterpillars and other insects, making it difficult, if not impossible for adult birds to feed their young. Why aren't there enough caterpillars and other insects present in backyards and home landscapes?  The simple answer is that they aren't there because the native trees, shrubs, and wildflowers that provide them with food and habitat aren't part of many residential landscapes. Compounding the problem is the use of pesticides in many lawns and gardens.

Residential landscapes are often filled with ornamental plants that originated in Asia, Europe, and other distant places. These ornamental plants, while beautiful and appealing to the human eye, have little or no value to insects that evolved in North America over thousands of years.

Because they evolved together, many insects depend upon very specific plants for their survival. If those plants aren't present, then neither are the insects that depend upon them.  Without insects, a backyard cannot offer baby birds the food they need to survive. Gardeners and homeowners can address that situation by adding a variety of native plants to their landscapes and reducing or eliminating the use of both herbicides and insecticides.

Pennsylvania has a variety of native trees, shrubs and flowering plants that can beautify a landscape and provide for the needs of insects, birds, and other wildlife.  Adding native trees and shrubs allows gardeners to follow nature's lead by creating layers that provide cover and habitat as well as flowers. Trees can create a canopy layer, shrubs an intermediate layer, and shorter plants the lowest layer. Here in Pennsylvania, a native white oak tree (Quercus) can support over 500 different species of caterpillar while providing nesting sites for birds and acorns for wildlife.  Native Tulip Tree (Liriodendron tulipifera) and Black Cherry (Prunus serotina) are flowering shade trees and host plants. Native redbuds (Cercis canadensis), which are covered in pink-lavender blooms in spring serve as host plants for Henry's Elfin butterflies.

Host plants are those which provide insect larvae with the food they need. Female butterflies seek out host plants and lay their egg on them so that when they hatch and become caterpillars, they have a readily available source of food in the leaves of those plants. Caterpillars will eat those leaves, grow, and eventually pupate into butterflies. While some might be concerned about caterpillars eating leaves and damaging plants, that's not the case with natives. Because native plants and insects have evolved together, the plants have learned to tolerate and bounce back from having their leaves eaten.  I remember a day last summer when some of my fellow Master Gardeners reacted with delight when they noticed that the leaves of some of the Butterfly weed (Asclepias tuberosa) in our demonstration gardens had been eaten. A quick check of the plants showed the presence of numerous caterpillars. Master Gardeners see that as a very good thing.  Those caterpillars would eventually become Monarch butterflies or protein-rich food for baby birds and the Butterfly weed would go on to grow new leaves. 

Spicebush (Lindera benzoin) and Blueberry (Vaccinium) can be good additions to the intermediate layer.  They provide cover and habitat as well as food for birds and insects and are host plants for certain butterflies. Winterberry, (Ilex verticillata) is a deciduous native holly with bright red berries that persist through the winter months, providing a source of food and a splash of color. Many other native shrubs are suitable for residential areas as well.

Native perennials can brighten a landscape from spring through fall here in Pennsylvania. In my yard, Dutchman's britches (Dicentra cucullaria) are among the first to bloom in spring and provide a profusion of creamy white blooms atop low-growing fern-like leaves. Wild blue phlox (Phlox divaricata) follows with fragrant periwinkle blue flowers that brighten shady spots. As the season progresses, False Indigo (Baptisa australis), Blazing Star (Liatris), Purple coneflower (Echinacea), Anise hyssop (Agastache foeniculum) and Butterfly weed (Asclepias tuberosa) take their turns adding color, and late bloomers such as Brown-eyed Susan (Rudbeckia fulgida var. fulgida) and New England aster (Symphyotrichum novae-angliae) produce clouds of flowers that are literally buzzing with insect activity as the season comes to an end. By allowing the dead stems and seed heads of these native perennials to remain in place through the winter, gardeners provide a source of seeds for birds and places for insects to seek cover at a time when those things are most needed. The dead material can then be removed in spring, allowing sunlight to reach new growth.

Must homeowners remove all their non-native plants? In many cases, that isn't necessary, especially if someone has a treasured ornamental such as a mature flowering Japanese cherry or other especially attractive non-native plant. A few prized ornamentals are fine, so long as there is plenty of space for natives.

One way to make room for natives to is to reduce the size of a lawn. Traditional lawns have very little to offer insects and other wildlife, especially those that contain only one type of turf and are treated with pesticides to maintain a so-called "perfect lawn." Those who want to help insects and birds can make their lawns much smaller and use that newfound space to plant natives. Not only will it help wildlife, it will save on the costs of maintaining a lawn.  Less gasoline, water, fertilizer and pesticides are needed and the amount of valuable time devoted to weekly mowing diminishes. Native plants typically require little or no supplemental water and fertilizer once established. They tend to be tougher than ornamentals because they are well suited to the conditions of their native regions.

When landscaping to support birds, insects, and other wildlife, pesticides, both herbicides (used to kill plants) and insecticides (used to kill insects) should be avoided.  Master Gardeners can provide information on decreasing pesticide use and alternatives for dealing with specific pest problems.

By going beyond birdseed and adding native plants, gardeners can help baby birds and other wildlife find the food they need. It's an opportunity to make a difference in our own backyards.